Ex post facto law

Ex post facto law, law that retroactively makes criminal conduct that was not criminal when performed, increases the punishment for crimes already committed, or changes the rules of procedure in force at the time an allegedcrime was committed in a way substantially disadvantageous to the accused.

The Constitution of the United States forbids Congress and the states to pass any ex post facto law. In 1798 it was determined that this prohibition applies only to criminal laws and is not a general restriction on retroactive legislation. Implicit in the prohibition is the notion that individuals can be punished only in accordance with standards ... (100 of 311 words)